U.S. patent application number 11/515896 was filed with the patent office on 2007-03-15 for laser processing apparatus and laser processing method as well as debris extraction mechanism and debris extraction method.
This patent application is currently assigned to Sony Corporation. Invention is credited to Kosei Aso, Hidehisa Murase, Yoshinari Sasaki, Naoki Yamada.
Application Number | 20070056941 11/515896 |
Document ID | / |
Family ID | 37854008 |
Filed Date | 2007-03-15 |
United States Patent
Application |
20070056941 |
Kind Code |
A1 |
Murase; Hidehisa ; et
al. |
March 15, 2007 |
Laser processing apparatus and laser processing method as well as
debris extraction mechanism and debris extraction method
Abstract
A laser processing apparatus is provided. The laser processing
apparatus removes and extracts debris generated by irradiating a
transparent resin layer formed on a substrate with laser light
during a patterning process, including debris extraction module
provided on the upper side of the substrate, wherein the debris
extraction module sucks and extracts debris due to sublimation,
thermal processing and composite action thereof generated from the
transparent resin layer on the substrate irradiated with the laser
light from the lower side thereof.
Inventors: |
Murase; Hidehisa; (Kanagawa,
JP) ; Sasaki; Yoshinari; (Tokyo, JP) ; Aso;
Kosei; (Kanagawa, JP) ; Yamada; Naoki;
(Kanagawa, JP) |
Correspondence
Address: |
RADER FISHMAN & GRAUER PLLC
LION BUILDING
1233 20TH STREET N.W., SUITE 501
WASHINGTON
DC
20036
US
|
Assignee: |
Sony Corporation
Tokyo
JP
141-0001
|
Family ID: |
37854008 |
Appl. No.: |
11/515896 |
Filed: |
September 6, 2006 |
Current U.S.
Class: |
219/121.84 |
Current CPC
Class: |
B23K 2103/50 20180801;
G02F 1/13439 20130101; B23K 2103/30 20180801; B23K 26/142
20151001 |
Class at
Publication: |
219/121.84 |
International
Class: |
B23K 26/14 20060101
B23K026/14 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 8, 2005 |
JP |
P2005-261248 |
Claims
1. A laser processing apparatus removing and extracting debris
generated by irradiating a transparent resin layer formed on a
substrate with laser light during a patterning process, comprising:
debris extraction means provided on the upper side of said
substrate, wherein said debris extraction means sucks and extracts
debris due to sublimation, thermal processing and composite action
thereof generated from said transparent resin layer on said
substrate irradiated with said laser light from the lower side of
the substrate.
2. A laser processing method of removing and extracting debris
generated by irradiating a transparent resin layer formed on a
substrate with laser light during a patterning process, comprising
the steps of: providing debris extraction module on the upper side
of said substrate; irradiating said transparent resin layer with
said laser light from the lower side of said substrate; and sucking
and extracting debris due to sublimation, thermal processing and
composite action thereof generated from said transparent resin
layer on said substrate by said debris extraction module.
3. A debris extraction mechanism removing and extracting debris
generated by irradiating a transparent resin layer formed on a
substrate with laser light during a patterning process, comprising:
debris extraction module provided on the upper side of said
substrate, wherein said debris extraction module sucks and extracts
debris due to sublimation, thermal processing and composite action
thereof generated from said transparent resin layer on said
substrate irradiated with said laser light from the lower side of
the substrate.
4. A debris extraction method of removing and extracting debris
generated by irradiating a transparent resin layer formed on a
substrate with laser light during a patterning process, comprising
the steps of: providing debris extraction module on the upper side
of said substrate; irradiating said substrate with said laser light
from the lower side of said substrate; and sucking and extracting
debris due to sublimation, thermal processing and composite action
thereof generated from said transparent resin layer on said
substrate by said debris extraction module.
5. A debris extraction mechanism according to claim 3, wherein a
thin film absorbing color of a wavelength of said laser light is
formed between said substrate and said transparent resin layer.
6. A debris extraction mechanism according to claim 5, wherein said
thin film is a black thin film absorbing said laser light of a
wavelength in the ultraviolet region.
7. A laser processing method according to claim 2, further
comprising the steps of: forming a thin film absorbing color of a
wavelength of said laser light on said transparent resin layer
formed on said substrate; defocusing said laser light on said thin
film irradiated from the lower side of said substrate; and forming
a pattern edge whose cross section is inverted cone-shaped in said
thin film.
8. A laser processing method of removing and extracting debris
generated by irradiating a transparent resin layer formed on a
multilayer film on a substrate with laser light during a patterning
process, comprising the steps of: forming a thin film absorbing
color of a wavelength of said laser light on said transparent resin
layer formed on said substrate; defocusing said laser light on said
thin film irradiated from the upper side of said substrate; and
forming a pattern edge whose cross section is cone-shaped in said
thin film.
9. A laser processing method according to claim 8, further
comprising the step of: focusing laser light precisely on said thin
film from the upper side of said substrate; focusing laser light
precisely on said thin film from the lower side of said substrate;
and forming a pattern edge whose cross section is vertical in said
thin film by irradiating said thin film with said laser light from
the upper and lower sides of said substrate.
10. A laser processing apparatus removing and extracting debris
generated by irradiating a transparent resin layer formed on a
substrate with laser light during a patterning process, comprising:
a debris extraction module provided on the upper side of said
substrate, wherein said debris extraction module sucks and extracts
debris due to sublimation, thermal processing and composite action
thereof generated from said transparent resin layer on said
substrate irradiated with said laser light from the lower side of
said substrate.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present invention contains subject matter related to
Japanese Patent Application JP 2005-261248 filed in the Japanese
Patent Office on Sep. 8, 2005, the entire contents of which being
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a laser processing
apparatus and a laser processing method for performing pattern
processing on a transparent conductive film used for a transparent
electrode on a multilayer thin film of an FPD (Flat Panel Display),
solar cell and the like. Particularly, the present invention
relates to a laser processing apparatus and a laser processing
method, as well as a debris extraction mechanism and a debris
extraction method for efficiently removing and extracting debris.
The debris is particles and products generated during laser
processing based on photochemical reaction (ablation), thermofusion
or composite action thereof in which a surface of a processing
object is irradiated with laser light from the lower side
thereof.
[0004] 2. Description of the Related Art
[0005] Resin materials are typically used as a resist material and
a planarizing material in a process of manufacturing a flat panel
display including a liquid crystal panel. A number of
photolithography processes are performed when patterning and
etching those resin materials. Hence, a huge facility investment
may be required, and a large amount of chemical solution is used,
which may cause damages to environment. In order to solve those
problems, there has been desired a technology of directly
patterning materials by using laser light. When laser processing is
performed in general, extraction of processing products called
debris becomes a major issue. Here, the debris is products
generated from a processed material having absorbed and reacted to
laser light and minute particles generated from the processed
material. Those products and particles are suspended and scattered
in the air and then re-deposited on a substrate. Particularly,
reaction products deposited on the substrate cause a defect in a
finished product, because such reaction products are hardened due
to temperature drop when re-deposited on the substrate and a
removal thereof is difficult even by scrubbing physically using a
brush or the like.
[0006] In the field of fine processing which deals with the flat
panel display including the liquid crystal panel, such
re-deposition of particles (dust) definitely causes defects.
Accordingly, a technology to extract debris may be required. A
transparent conductive film is typically patterned into a desired
shape by a photolithography method. For example, a transparent
conductive film made of an ITO (Indium Tin Oxides) film, ZnO (Zinc
Oxides) film or the like is vacuum-coated on a glass, plastic or
silicon-wafer substrate and the like. Then a resist layer is formed
thereon to be exposed by irradiation of light through a photomask
having a predetermined pattern. The photomask pattern is
transcribed onto the resist layer by performing development and
post bake, then a portion of the transparent conductive film not
covered with the resist is removed by wet etching, and the
remaining resist layer is removed at the end so that the desired
pattern of the transparent conductive film is obtained.
[0007] However, the photolithography process described above may
need a large scale apparatus such as a coater/developer, which
causes a problem in view of facility investment and footprint. In
addition, since a large amount of chemical solution such as
developing solution is used, there is also caused a problem in view
of environmental preservation. Japanese Published Patent
Application No. 2004-153171 discloses technology for directly
processing a transparent conductive film by using laser light, with
which a manufacturing process is simplified by omitting a
photolithography process.
[0008] Japanese Published Patent Application No. 2004-188451
discloses a laser processing method and a laser processing
apparatus, in which a surface of a processing object is irradiated
with laser light, causing debris generated from a region irradiated
with laser to be deposited on an adsorption panel by a magnetic
field. By doing so, there is obtained a laser processing method in
which debris generated by laser processing is prevented from being
re-deposited on the processed surface when the processing based on
ablation or thermofusion is performed by irradiating the surface of
the processing object with the laser light. According to the laser
processing methods disclosed in the above-described Patent
References, the processing object is irradiated with laser light
from the upper side thereof. Therefore, debris from the processing
object is scattered in all directions.
[0009] Further, Japanese Published Patent Application No.
2002-126890 discloses a debris extraction technology in which a
duct for extracting dust, whose shape and distance from the
processed surface has been studied, is provided in the case where
laser light is used to perform processing of drilling a metal plate
used for an industrial purpose. Further, Japanese Published Patent
Application No. 2000-317670 discloses a method of extracting debris
by air flow while physically covering an area of irradiated
portion. Furthermore, Japanese Published Patent Application No.
09-271980 discloses a method of sucking debris in which the
vicinity of irradiated portion is made into a double structure
using a kind of curtain.
[0010] Moreover, Japanese Published Patent Application No. 10-99978
discloses a method of reducing debris deposited onto a substrate.
In this method are provided a fluid delivery apparatus blowing a
gas onto a surface in the vicinity of a processed region and a
suction duct sucking a fluid on the opposite side. Then, debris is
blown off the processed region and simultaneously sucked and
removed.
[0011] FIG. 1 shows a configuration disclosed in the
above-described Japanese Published Patent Application No. 10-99978.
An apparatus shown in FIG. 1 is a laser processing apparatus for
stamping a manufacturer's serial number on a glass substrate 5
arranged in part of a manufacturing process for preparing a
predetermined product. In this manufacturing process, various
coating processing and patterning are performed on the glass
substrate 5 through a series of processes using a plurality of
processing machines. This laser processing apparatus includes: a
processing table 20, a laser irradiation apparatus 22, a fluid feed
apparatus 24, and a discharge apparatus 26. The processing table 20
moves in two directions parallel with a plane of the glass
substrate mounted 5 to determine the position of a stamp region 21
where the manufacturer's serial number is stamped. The laser
irradiation apparatus 22 stamps the manufacturer's serial number
corresponding to the kind of the mounted glass substrate 5 onto the
stamp region 21. The fluid feed apparatus 24 has a blow nozzle 23
for directing a fluid to the stamp region 21 of the glass substrate
5 mounted on the processing table 20. The discharge apparatus 26
has a suction duct 28 for sucking the fluid over the stamp region
21. Debris 7 generated by irradiating a black matrix 27 of the
stamp region 21 with laser light 1a is removed by processing using
the laser light 1a emitted from a laser oscillator 1 through an
objective lens 25 of the laser irradiation apparatus 22.
[0012] However, debris is intended to be extracted in those patent
references to the extent of not affecting a human body. Hence, it
is difficult to control and extract particle patterns in the order
of several .mu.m to several tens .mu.m, which can be applied to
processing of a fine device such as a transparent conductive film
formed on a glass substrate of a liquid crystal panel.
[0013] Further, a reaction mechanism called ablation as described
above may occur in the range of a wavelength of excimer lasers to
be used as a laser source, for example. In the ablation processing,
energy of the laser light is absorbed by a material to be
processed, disintegrating the material without generating heat by
disrupting chemical bonds that forms a molecular frame.
Consequently, it is said that less debris is generated. In
addition, a simplified debris extraction method of only blowing a
helium (He) gas, nitrogen (N.sub.2) gas or the like is typically
used. However, there are practically not many cases in which the
processing of fine devices can be performed only by the ablation of
photochemical reaction but in most cases a composite process
including a heat-affected process is used.
[0014] Further, a semiconductor-process-applied product such as a
liquid crystal panel has a complicated film structure as a material
thereof, and therefore a different phenomenon occurs compared with
a single-layer film. When a plurality of process factors are thus
mixed, the debris extraction becomes complicated and it is
necessary to analyze a debris generation mechanism in details and
to develop a debris extraction method suitable for each case. At
present, a transparent conductive film is used as a transparent
electrode of a multilayer film substrate for a flat display panel,
of a solar cell and the like. Also a transparent conductive film is
widely used as a transparent electrode in the field of electronic
paper whose development has been promoted as a future display
device, and the use thereof has been expanded. Further, since
competition for higher definition and lower costs of a display has
become more intensive recently, a transparent conductive film of
higher quality and higher productivity may also be required in
manufacturing a display. Accordingly, the inventors of the present
application recognize a necessity to analyze the debris generation
mechanism in details and to obtain a laser processing apparatus and
a laser processing method as well as a debris extraction mechanism
and a debris extraction method which are suitable for each
case.
SUMMARY OF THE INVENTION
[0015] In the case where a laser processing method using a laser is
performed on manufacturing a flat display panel, solar cell and the
like, there is a need for extracting debris efficiently by
analyzing a mechanism in which debris is generated with the
irradiation of laser light and by using a result of the analysis.
Further, a patterning method performed in the photolithography
process in the past is replaced with a patterning method using
laser light, thereby reducing investment, reducing burden on the
environment, reducing manufacturing costs and reducing a
footprint.
[0016] It is desirable to provide a laser processing apparatus and
a laser processing method as well as a debris extraction mechanism
and a debris extraction method, in which a transparent resin layer
formed on a substrate is irradiated with laser light from the lower
side of the substrate and debris is generated isotropically on the
upper side of the substrate when etching and patterning the
transparent resin layer.
[0017] It is further desirable to provide a laser processing
apparatus and a laser processing method as well as a debris
extraction mechanism and a debris extraction method, in which a
black resin layer is added between the surface of the substrate and
the transparent resin layer. With the black resin layer being
provided, energy of laser light can further be absorbed to vaporize
the black resin layer, causing debris generated from a transparent
film to be scattered upward by means of abrupt volume expansion
thereof when irradiated with the laser light from the lower side of
the substrate.
[0018] It is further desirable to provide a laser processing
apparatus and a laser processing method as well as a debris
extraction mechanism and a debris extraction method, in which a
debris extraction mechanism is provided on the upper side of the
substrate and the substrate is irradiated with the laser light from
the lower side thereof.
[0019] It is further desirable to provide a laser processing
apparatus and a laser processing method as well as a debris
extraction mechanism and a debris extraction method, in which a
black resin layer easily absorbing laser light is formed on a
transparent resin layer, the laser light being focused on the black
resin layer, a fine adjustment being performed with respect to the
focusing on the surface, a processed shape of a patterning edge
being controlled.
[0020] According to an embodiment of the present invention, there
is provided a laser processing apparatus removing and extracting
debris generated by irradiating a transparent resin layer formed on
a substrate with laser light during a patterning process. The laser
processing apparatus includes a debris extraction module on the
upper side of the substrate. The debris extraction module sucks and
extracts debris due to sublimation, thermal processing and
composite action thereof generated from the transparent resin layer
on the substrate irradiated with the laser light from the lower
side of the substrate.
[0021] According to another embodiment of the present invention,
there is provided a laser processing method of removing and
extracting debris generated by irradiating a transparent resin
layer formed on a substrate with laser light during a patterning
process. The method includes the steps of: providing debris
extraction module on the upper side of the substrate; irradiating
the transparent resin layer with the laser light from the lower
side of the substrate; and sucking and extracting debris due to
sublimation, thermal processing and composite action thereof
generated from the transparent resin layer on the substrate by the
debris extraction module.
[0022] According to further embodiment of the present invention,
there is provided a debris extraction mechanism removing and
extracting debris generated by irradiating a transparent resin
layer formed on a substrate with laser light during a patterning
process. The debris extraction mechanism includes debris extraction
module provided on the upper side of the substrate. The debris
extraction module sucks and extracts the debris due to sublimation,
thermal processing and composite action thereof generated from the
transparent resin layer on the substrate irradiated with the laser
light from the lower side thereof.
[0023] According to further another embodiment of the present
invention, there is provided a debris extraction method removing
and extracting debris generated by irradiating a transparent resin
layer formed on the substrate with laser light during the
patterning process. The debris extraction method includes the steps
of: providing debris extraction module on the upper side of the
substrate; irradiating the transparent resin layer with the laser
light from the lower side of the substrate; and
[0024] sucking and extracting debris due to sublimation, thermal
processing and composite action thereof generated from the
transparent resin layer on the substrate by the debris extraction
module.
[0025] According to still another embodiment of the present
invention, there is provided a laser processing apparatus removing
and extracting debris generated by irradiating a transparent resin
layer formed on a multilayer film on a substrate with laser light
during the patterning process. The laser processing apparatus
includes a thin film absorbing color of a wavelength of the laser
light formed on the transparent resin layer on the substrate. The
laser light is defocused on the thin film irradiated from the upper
side of the substrate and a pattern edge whose cross section is
cone-shaped is formed in the thin film.
[0026] According to still another embodiment of the present
invention, there is provided a laser processing apparatus including
a thin film absorbing color of a wavelength of laser light formed
on the transparent resin layer on the substrate. The laser light is
defocused on the thin film irradiated from the upper side or lower
side of the substrate and a pattern edge whose cross section is
cone-shaped or inverted cone-shaped is formed in the thin film.
[0027] According to the above-described embodiments of the laser
processing apparatus and laser processing method as well as debris
extraction mechanism and debris extraction method, there is
provided the debris extraction module capable of extracting
efficiently debris generated when patterning a transparent
conductive film formed on the multilayer film on the substrate.
[0028] According to the above-described embodiments of the laser
processing apparatuses, the resin layer having the predetermined
pattern shape is obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is an schematic constitutional diagram showing an
example of a laser processing apparatus of related art;
[0030] FIG. 2 is an overall constitutional diagram showing a laser
processing apparatus according to an embodiment of the present
invention;
[0031] FIGS. 3A through 3F are sectional side views of a substrate,
showing a process of forming a multilayer thin film on the
substrate in order to explain a debris generation mechanism
according to an embodiment of the present invention;
[0032] FIGS. 4A through 4F are sectional side views of a substrate,
showing a process of forming a multilayer thin film on the
substrate in order to explain a debris generation mechanism
according to another embodiment of the present invention;
[0033] FIGS. 5A to 5C are sectional side views of a substrate in
order to explain a method of processing a film formed in the laser
processing apparatus according to an embodiment of the present
invention;
[0034] FIGS. 6A and 6B are sectional side views of a substrate in
order to explain a method of processing a film formed in the laser
processing apparatus according to another embodiment of the present
invention; and
[0035] FIGS. 7A and 7B are sectional side views of a substrate in
order to explain a method of processing a film formed in the laser
processing apparatus according to further another embodiment of the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] An embodiment of the present invention is explained in the
followings with referring to FIGS. 2 through 7. FIG. 2 is an
overall constitutional diagram showing a laser processing apparatus
according to an embodiment of the present invention. FIGS. 3A
through 3F are sectional side views of a substrate, showing a
process of forming a multilayer thin film on the substrate in order
to explain a debris generation mechanism according to an embodiment
of the present invention. FIGS. 4A through 4F are sectional side
views of a substrate showing a process of forming a multilayer thin
film on the substrate in order to explain a debris generation
mechanism according to another embodiment of the present invention.
FIGS. 5A to 5C are sectional side views of a substrate in order to
explain a method of processing a film formed in the laser
processing apparatus according to an embodiment of the present
invention. FIGS. 6A and 6B are sectional side views of a substrate
in order to explain a method of processing a film formed in the
laser processing apparatus according to another embodiment of the
present invention. FIGS. 7A and 7B are sectional side views of a
substrate in order to explain a method of processing a film formed
in the laser processing apparatus according to further another
embodiment of the present invention.
[0037] According to the embodiments of the present invention, there
are provided a laser processing apparatus and a laser processing
method as well as a debris extraction mechanism and a debris
extraction method for removing and extracting debris. The debris is
particles and products generated during laser processing based on
ablation, thermofusion or combined action thereof. Specifically,
when forming a transparent conductive film and a transparent resin
layer on a multilayer film formed on a glass substrate that is a
processing object, the surface of the transparent resin layer is
irradiated with laser light from the lower side of the substrate,
generating debris to be extracted.
[0038] Hereinafter, an embodiment of a laser processing apparatus
according to the present invention is explained with referring to
FIG. 2. FIG. 2 schematically shows a laser optical system and a
debris extraction mechanism according to the embodiment of the
present invention. Laser light 1a shown in FIG. 2 is emitted from a
laser oscillator 1 having a laser light source. The laser light 1a
passes through a planarizing optical system 2 including a
homogenizer and a diffraction grating, for example, and is
planarized such that energy from the laser light source becomes
uniform. The laser light 1a is shaped into a laser beam 3a of a
desired beam size by a variable aperture 3 that determines the size
thereof. Then, the laser beam 3a whose size is determined by the
variable aperture 3 is reduced and focused by a reduction
projection lens 4. Consequently, a transparent resin layer 8 formed
on a multilayer film on the surface of a substrate 5 made of, for
example, glass is irradiated with the laser beam 3 from the lower
side of the substrate 5. A debris extraction mechanism 6 is
provided above the substrate 5 so that debris 7 generated from the
transparent resin layer 8 is extracted by the debris extraction
mechanism 6.
[0039] An excimer laser, for example, is used for the laser light
source of the laser oscillator 1 shown in FIG. 2. There exist
plural kinds of excimer laser each having different laser medium,
and those are XeF (351 nm), XeCl (308 nm), KrF (248 nm), ArF (193
nm) and F.sub.2 (157 nm) in order of increasing wavelength.
However, it should be appreciated that the laser is not limited to
an excimer laser but may be a solid-state laser, CO.sub.2 laser or
the like. The planarizing optical system 2 shapes the laser light
1a emitted from the laser light source and reflected by a mirror,
and outputs the laser light after homogenizing a beam intensity.
For example, a perforated mask of a predetermined aperture formed
of a metal material, a photomask formed of a transparent glass
material or metal thin film, a dielectric mask formed of a
dielectric material, and a variable aperture capable of varying an
aperture are used for the variable aperture 3.
[0040] After passing through the aperture 3, the laser light 1a has
a predetermined beam diameter. A laser beam 3a having passed
through the aperture 3 is projected with a predetermined reduction
magnification through the reduction projection lens 4 onto a
processed surface of the transparent resin layer 8 that is a
processing object on the substrate 5. The reduction projection lens
4 is disposed such that the laser light projected from the
reduction projection lens 4 is focused onto the processed surface
of the transparent resin layer 8 formed on the substrate 5. The
substrate 5 is arranged on a stage not shown in the figure and is
capable of being moved and positioned along a horizontal plane
perpendicular to an optical axis of the laser beam 3a. Therefore,
the processed surface of the transparent resin layer 8 can be
scanned by the laser beam 3a emitted from the laser oscillator 1
passing through a through hole provided in the stage.
[0041] FIGS. 3A through 3F show a debris generation mechanism in
the case where the above-described laser processing apparatus is
used and the wavelength of the laser light 1a emitted from the
laser oscillator 1 is of light a large amount of which is absorbed
into the transparent resin layer 8. First, as shown in FIG. 3A, a
boundary surface 9 between the substrate 5 made of, for example,
glass and the transparent resin layer 8 formed thereon is
irradiated with the laser beam 3a emitted from the laser source
from the lower side through the transparent substrate 5.
Subsequently, as shown in FIG. 3B, fusion due to thermal reaction,
sublimation due to ablation reaction and composite action of
physical destruction occur, causing the lower surface of the
transparent resin layer 8 to be etched. In this regard, since the
transparent resin layer 8 is irradiated with the laser beam 3a from
the lower side of the substrate 5, the transparent resin layer 8
absorbs energy of the laser beam 3a through the boundary surface 9
between the substrate 5 and the transparent resin layer 8.
Accordingly, as shown in FIG. 3C, a thermal etching portion 10a is
formed due to heating on the etched portion.
[0042] When the energy of the laser beam 3a exceeds a threshold
value of vaporization heat in the transparent resin layer 8, the
transparent resin layer 8 instantly vaporizes from a solid state.
Accordingly, as shown in FIG. 3D, the volume of the thermal etching
portion 10a abruptly expands on the boundary surface 9 to form a
volume-expanded portion 10b.
[0043] Further, the transparent resin layer 8 is pushed upward to
make micro cracks, and eventually, as shown in FIGS. 3E and 3F, the
transparent resin layer 8 is isotropically broken upward, causing
the broken pieces scattering like an explosion to become
debris.
[0044] Next, FIGS. 4A through 4F show such case that the wavelength
of the laser light 1a emitted from the laser source of the laser
oscillator 1 is of light a small amount of which is absorbed into
the transparent resin 8. In this regard, a layer capable of easily
absorbing the laser light such as a black resin layer 11, for
example, is interposed between the substrate 5 and the transparent
resin layer 8. More specifically, as shown in FIG. 4A, the black
resin layer 11 is formed on a boundary surface 9a with the glass
substrate 5, and the transparent resin layer 8 is formed on the
black resin layer 11. Since the laser light 1a of a wavelength in
ultraviolet region is used in this embodiment, a color of the resin
layer 11 is black, but the color is not specifically limited to
black as long as the resin layer is a color layer that can easily
absorb laser light of the wavelength to be used. Therefore, the
resin layer is called the black resin layer 11 in this embodiment,
and that is an example of color layers each absorbing color
corresponding to the wavelength.
[0045] Specifically, FIGS. 4A through 4F show a debris generation
mechanism in the case where the laser processing apparatus shown in
FIG. 2 is used and the wavelength of the laser light 1a emitted
from the laser oscillator 1 is of light a small amount of which is
absorbed into the transparent resin layer 8 through a color layer
absorbing color corresponding to the wavelength. As shown in FIG.
4A, the color layer (here, the black resin layer) 11 that absorbs
color corresponding to the wavelength of the laser beam 3a is
formed on the substrate 5 made of, for example, glass. The
transparent resin layer 8 is formed on this black resin layer 11.
When, as shown in FIG. 4B, a boundary surface 9a between the
substrate 5 made of, for example, glass and the black resin layer
11 is irradiated from the lower side through the transparent
substrate 5 with the laser beam 3a emitted from the laser source,
the energy of the laser beam 3a is absorbed into the black resin
layer 11 to be heated, causing a heated portion 11a to be
formed.
[0046] When the energy of the laser beam 3a exceeds a threshold
value of the transparent resin layer 8, the thermal etching portion
10a of the transparent resin layer 8 shown in FIG. 4C is heated.
Further, the heated portion 11a of the black resin layer 11 having
absorbed the energy vaporizes to cause the abrupt volume-expanded
portion 10b. Furthermore, when exceeding the vaporization heat, the
heated portion 11a having absorbed further energy is vaporized
instantly from the solid state to cause the abrupt volume
expansion. As shown in FIG. 4D, micro cracks 10c are generated in
the thermal etching portion 10a of the transparent resin layer 8.
Consequently, as shown in FIGS. 4E and 4F, the transparent resin
layer 8 is broken isotropically upward, scattering like an
explosion to become debris.
[0047] Since the debris 7 is scattered isotropically upward when
those debris generation mechanisms are used, the debris 7 in the
order of several .mu.m to several tens .mu.m patterns can be
extracted efficiently during the pattern shaping with the debris
extraction mechanism 6 being provided on the upper side. In
addition, generation of the micro cracks and the size of debris can
be controlled by selecting a method of absorbing the energy and by
adjusting an intensity of the energy.
[0048] Next, FIGS. 5A, 5B and 5C show a method of processing the
edge of an etching pattern of a processing object into a desired
shape in the case where the irradiation of laser beams 3a and 3b
are performed from the lower and upper directions of the substrate
5. As shown in FIG. 5A, when the wavelength of, for example, the
ultraviolet ray is used and light is absorbed into the color layer
absorbing color of the wavelength of the laser light 1a, with which
the transparent resin layer 8 formed on the substrate 5 is
irradiated, a resin layer 11b made of a black thin film is added.
The resin layer 11b of this thin film may be a black resin layer,
but it is also possible to color the layer simply with an organic
material such as a paint using a felt pen. As shown in FIG. 5C that
is a magnified view of a portion A in FIG. 5A, this resin layer 11b
is irradiated with the laser light 1a such that the upper-side
laser beam 3b and lower-side laser beam 3a are exactly focused on
points F1 and F2 on the front and back surfaces of the resin layer
11b respectively, with focal depths of the objective lens 25 and
reduction projection lens 4 in FIG. 1 being adjusted. By doing so,
as shown in FIG. 5B, an edge of the etching pattern can be
processed into the edge having an approximately vertical shape
12.
[0049] On the other hand, when a focal point F3 of the laser beam
3a from the lower side is shifted upward as shown in FIG. 6A, the
edge of an etching pattern becomes an inverted tapered-shape 13
having an inverted cone shape as shown in FIG. 6B. Further, when a
focal point F4 of the laser beam 3b from the upper side is shifted
downward as shown in FIG. 7A, the edge of an etching pattern
becomes a tapered-shape 14 having a cone shape as shown in FIG. 7B.
It is conceivable that those phenomena occur due to the fact that
beam profiles greatly affect the processing when the absorption of
energy increases by the color of the resin layer 11a being black.
Although the above-described embodiment is explained with respect
to the transparent resin layer in the production of a liquid
crystal panel, it should be appreciated that the transparent resin
layer is not limited to that of resin materials but may also be a
transparent conductive film and the like such as ITO.
[0050] According to the embodiments of the laser processing
apparatus and the laser processing method as well as the debris
extraction mechanism and the debris extraction method, the
followings can be obtained:
(A) Debris can be isotropically generated upward by irradiating a
transparent resin layer efficiently absorbing laser with laser
light from the lower side;
(B) Debris can be isotropically generated upward by adding a resin
layer easily absorbing laser light such as a black resin layer to a
transparent resin layer not easily absorbing laser light;
(C) With the above-described (A) and (B), the debris extracting
rate can be greatly improved by providing a debris extraction
mechanism on the upper side;
(D) A desired shape of the pattern edge can be obtained by adding
the black resin layer to the substrate; and
(E) With the above-described (C) and (D), patterning is directly
performed using the laser, and such direct patterning can replace
the patterning performed in the photolithography process in the
past.
[0051] It should be understood by those skilled in the art that
various modifications, combinations, sub-combinations and
alterations may occur depending on design requirements and other
factors insofar as they are within the scope of the appended claims
or the equivalents thereof.
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